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King's College Criteria for Liver Transplantation
The King's College Criteria (KCC) were first described by O'Grady et al. (Gastroenterology, 1989) from King's College Hospital, London. They are the most widely used prognostic tool for identifying patients with acute liver failure (ALF) who are unlikely to survive without liver transplantation. The criteria are divided by etiology:
A. Paracetamol (Acetaminophen)-Induced ALF
Transplantation is indicated if either of the following is present:
Criterion 1 (single):
- Arterial pH < 7.30 - after adequate resuscitation (irrespective of grade of encephalopathy)
OR
Criterion 2 (all three must be present simultaneously):
| Parameter | Threshold |
|---|
| Prothrombin time (PT) | > 100 seconds (INR > 6.5) |
| Serum creatinine | > 300 µmol/L (> 3.4 mg/dL) |
| Hepatic encephalopathy | Grade III or IV |
The triad of severe coagulopathy + renal failure + advanced encephalopathy (in a paracetamol patient) carries a very poor prognosis.
B. Non-Paracetamol ALF
Transplantation is indicated if either of the following is present:
Criterion 1 (single):
- PT > 100 seconds (INR > 6.5) - irrespective of grade of encephalopathy
OR
Criterion 2 (any 3 of these 5 variables):
| Variable | Threshold |
|---|
| Age | < 10 years or > 40 years |
| Etiology | Non-A, non-B hepatitis; idiosyncratic drug reactions; halothane hepatitis |
| Jaundice-to-encephalopathy interval | > 7 days |
| PT | > 50 seconds (INR > 3.5) |
| Serum bilirubin | > 300 µmol/L (> 17.6-18 mg/dL) |
Modified KCC - Lactate/Phosphate Addition
Subsequent modifications to the original criteria have been proposed to improve sensitivity and negative predictive value:
- Serum lactate > 3.5 mmol/L at 4 hours (or > 3.0 mmol/L after resuscitation) has been added as a strong predictor in paracetamol-induced ALF
- Hyperphosphataemia is also a strong independent predictor of poor prognosis without transplantation
These additions are particularly useful in paracetamol cases to improve sensitivity of the original criteria.
Performance of the KCC
| Metric | Value |
|---|
| Positive predictive value (PPV) | 80-100% (high specificity - if criteria met, patient very likely to die without transplant) |
| Negative predictive value (NPV) | Drops below 50% in non-paracetamol ALF |
| Main weakness | Low NPV means patients not meeting criteria can still die without transplantation |
The high PPV makes the KCC excellent at identifying who will die without a transplant, but its low NPV means some patients who don't meet criteria may still need transplantation. This is particularly relevant in non-paracetamol etiologies.
Comparison with Other Systems
| System | Basis | Note |
|---|
| King's College Criteria | PT, creatinine, pH, bilirubin, etiology, age | Distinguishes paracetamol vs. non-paracetamol |
| Clichy (Paul Brousse) Criteria | Age + Factor V levels | Stage III/IV coma + Factor V <20% (<30 yrs) or <30% (>30 yrs); no etiology distinction |
| MELD Score | Bilirubin, creatinine, INR | Used mainly for chronic liver disease; less specific for ALF |
| APACHE II / SOFA | Multi-organ failure scoring | Alternative prognostic models in ALF |
Clinical Context
- If cerebral edema is evident on CT scan, the likelihood of irreversible brain injury or herniation is high - transplantation is contraindicated at that stage
- In patients meeting KCC, liver transplantation remains the only definitive treatment for fulminant hepatic failure
- Post-transplant survival in ALF: ~73% at 1 year, ~67% at 5 years (older data); more recent registry data shows improved 1-year graft survival of ~80%
Sources:
- Bailey and Love's Short Practice of Surgery, 28e, Summary Box 69.5
- Barash, Cullen & Stoelting's Clinical Anesthesia, 9e, Table 46-5
- Current Surgical Therapy, 14e, Box 1 - King's College Criteria
- O'Grady JG et al. Early indicators of prognosis in fulminant liver failure. Gastroenterology. 1989;97:439